where \(N(\epsilon , m, \Vert \cdot \Vert _2)\)  is the \(\epsilon \) -covering
number of \(m\)  under the \(L_2\)  metric. Our proof of
(REF ) is based on establishing a connection between the
metric entropy of \(m\)  and the small ball probability of integrated
Brownian sheet (using ideas
and results from [1]}, [2]}, [3]}, and
[4]}) and then
deriving the small ball probability of integrated Brownian sheet
(using ideas and results from [5]} and
[6]}).
